since both are sales monsters, which do you see reaching the prestigious 100m mark faster, when launch-alligned?

Definitely PS4.

Too early to tell, we'll know more after year 2-3 for Switch

PS4, Sony has a bigger structure and infrastructure. And the Play Station brand is enjoying popularity in all the markets.

PS4 is already 3 quarters there. It's a safe assumption to say that it will be the PS4.

Ignore, I missed the "when launch aligned" statement.

My lifetime estimates for Switch is 90-95M at this moment (due to nintendo replacing their consoles fairly quickly), so PS4 by default.

I wont be surprised if the Switch does manage to crush the 100 million mark, though.

launch  alligned

PS4 anyway

I don't agree with Nintendo replacing consoles quickly. Most of their consoles release when the competition does. The only short ones was the GBA and Wii U. 

Nintendo has been talking about letting the Switch last longer than the normal 5 to 6 years already. It sounds like they want a short lifespan. Also I the 3DS --> Switch lifespan is 6 years. That is a normal lifespan for a console. The Wii U --> Switch is only short because Nintendo combined the home and handheld console hardware. 

I just don't see Nintendo releasing a new console soon. The Switch is already a really powerful handheld. Probably the strongest they can make it right now. I just don't see how they can justify a new console so soon unless they come up with some crazy good idea. If Nintendo is just going to release a more powerful Switch than it is best to wait at least 6 years from now. I.E not a short lifespan.

So 100 million should be more than doable unless Nintendo decides to make a lot of bad mistakes.